Download - Chapter 1 the Scope of Physics
CHAPTER 1THE SCOPE OF PHYSICS
CONTAIN:1. INTRODUCTION 2. SYSTEM OF UNITS (MEASUREMENT). 3. DIMENSION. 4. UNIT AND DIMENTION5. SIGNIFICANT FIGURE
DESCRIPTIVE PART 1: What is PHYSICS? The word 'Physics' comes from the Greek word 'phusis' meaning 'nature', introduced by the ancient scientist 'Aristotle'. Man has always been fascinated by nature. The branch of science which is devoted to the study of nature and natural phenomena is called Physics. It is expected that all the events in nature take place according to some basic laws. Thus Physics (the knowledge of nature) is the science concerned with the discovery and understanding of the most basic fundamental laws of the universe that control the way everything in the world around us behaves. Discoveries in basic physics have important ramifications for all of science. Physics is the scientific study of matter and energy and how they interact with each other. Physics deals with matter on scales ranging from sub-atomic particles (i.e. the particles that make up the atom and the particles that make up those particles) to stars and even entire galaxies. Physics is the truly universal science. There are many fields of physics, for example: mechanics, electricity, heat, sound, light, condensed matter, atomic physics, nuclear physics, and elementary particle physics. Physics is the foundation of all the physical sciences, such as chemistry, material science, and geology and is important for many other fields: biology, medicine, computing, ice hockey, and television, list goes on.The physics was divided in main two branches:
i. Classical mechanics ii. Quantum mechanics.
The Mechanics or classical physics is an important field of physics. Developed by Sir Isaac Newton in the 17th century, the laws of mechanics and the law of gravity successfully explained the orbits of the moon around the earth and the planets around the sun. Newton’s laws are used to design cars, clocks, airplanes, earth satellites, bridges, buildings, just about everything, it seems, except electronics.
Electricity is another example of physics, one that you may experience as a spark when you touch a doorknob on a dry winter day. The electrical attraction of protons and electrons is the basis for chemistry. Magnetism is another force of nature, familiar to us from refrigerator magnets and compasses. In the 19th century, James Clerk Maxwell combined electricity and magnetism. He showed that light is an electromagnetic wave that travels through empty space. The Quantum mechanics deals Einstein’s theory of relativity and other modern concepts of twentieth century are discussed. The modern physics divided in to: Atomic physics, Elementary physics, Nuclear physics, Molecular physics, Plasma physics, Medical physics, Solid state physics, Astronomical physics, and many others.
2: Physical Quantities:Physical quantity is the numerical value of a measurable property that describes a physical system's state at a moment in time.Extensive and Intensive Quantities:Extensive: when its magnitude is additive for subsystems (volume, mass, etc.)Intensive when the magnitude is independent of the extent of the system (temperature, pressure, etc.)
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Some physical quantities are prefixed in order to further qualify their meaning:Molar is added to refer to a quantity which is expressed per unit mass (such as specific heat capacity)Specific is added to refer to a quantity which is expressed per unit amount of substance (such as molar volume).
There are also physical quantities that can be classified as neither extensive nor intensive, for example angular momentum, area, force, length, and timeCoordinates are sets of numbers that describe position along a line, on a surface or in space. Latitude and longitude, or declination and right ascension, each is a system of coordinates on the surface of a sphere on the globe of the Earth or the globe of the heavens.
3: Unit: Unit is the universally accepted definite amount of a physical quantity taken as a standard for the measurement of the same physical quantity of any amount. E.g. Kilogram (kg), meter (m), second (s), and etc some physical quantities have no units, since each is expressed by a ratio of similar physical quantities. For example, mechanical advantage, velocity ratio, refractive index, atomic weight, and etc. It means, a unit is a particular physical quantity, defined and adopted by convention, with which other particular quantities of the same kind are compared to express their value.
4: Fundamental Quantities: The first standard units of measurement were established by the French Academy of Sciences in the 1790. The measurement of any quantity is made relative to particular standard or unit and this unit must be specified along with the numerical value of the quantity. Fixing the unit of only three physical quantities forms a system of units, which contains the unit of every physical quantity. These quantities are called “fundamental quantities”, and their units are called “fundamental units”. A physical quantity is a physical property that can be quantified. This means it can be measured or calculated and expressed in numbers. For example, "mass" is a physical quantity that can be expressed by stating a number of some basic measurement units. A quantity of mass might be represented by the symbol m, and could be expressed in the unit’s kilograms.
Basic SI quantities:The International System of Units SI is the modern form of the metric system. The SI was developed in 1960 from the old meter-kilogram-second (MKS) system, rather than the centimeter-gram-second (CGS) system. The system is nearly universally employed. In all there are seven SI base units: the meter for distance, the kilogram for mass, the second for time, the ampere for electric current, the Kelvin for temperature, the mole for amount of substance, and the candela for intensity of light.
5: Derived Quantities:The quantities other than fundamental quantities are, called derived quantities, are defined in terms of the seven base quantities via a system of quantity equations. Thus, Derived physical quantities are those, each of which associates one or more fundamental physical quantities. The SI derived units for these derived quantities are obtained from these equations and the seven SI base units.
6: System of Units:Measurements have an important role not only in physics but also in every branch of science and everywhere in our day-to-day life. To solve problems and to understand the basics of the Physics it is very important to know what is a physical quantity, types of physical quantities, what is a unit, what are the units of different physical quantities, types of units, symbols of units.
1. S.I. System of units:In 1960, an international committee established a set of standards for length, mass, and other basic quantities. The system established is an adaptation of the metric system, and it is called the SI system of units. In this system, the units of length, mass, and time are the meter, kilogram, and second, respectively. Other SI standards established by the committee are those for temperature (the Kelvin), electric current (the ampere), luminous intensity (the candela), and the amount of substance (the mole). The laws of physics are expressed in terms of basic quantities that require a clear definition. In mechanics, the three basic quantities are length (L), mass (M), and time (T). All other quantities in mechanics can be expressed in terms of these three.
Set of fundamental and derived units for the accurate measurement of physical quantities is called “system of units”.
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There are seven base units of the SI:i. The Meter:
The unit of length as the meter was defined as the distance between two fixed points on a platinum–iridium bar stored under controlled conditions kept at the International Bureau of Weights and Measures at Sevres, France.
In the 1960s and 1970s. Meter the unit of length is defined as 1650763.73 times the wave length of orange light emitted by
krypton -86 atoms. In October 1983, the meter (m) was again redefined as the distance traveled by light in vacuum during a
time of second.1m = 100 cm1 cm =10 mm
ii. The Kilogram: One kilogram defined as the mass of a platinum-iridium cylinder3.9cm in diameter and 3.9cm in height
kept at the International Bureau of Weight and Measurement at Sevres, France, established in 18871 kilogram = 1000 gm1gm = 1000 mg
One a.m.u or u is used as the unit of mass in atomic physics. Mass of a C12 atom is 12 atomic mass units. One u is defined as 1/12th of the mass of one C12 atom.
iii. The Second Before 1960, the standard of time was defined in terms of the mean solar day for the year 1900. The one
second was originally defined as of a mean solar day. In 1967, the atomic clock was adopted, choosing caesium-133 atom, which emits electromagnetic
radiation of a precise and unvarying frequency, corresponding to the transition between two hyperfine levels of the ground state.
The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom
1day = 24 hours1hour = 60 min. 1min = 60 sec.
iv. The Ampere The ampere is that constant current which, if maintained in two straight parallel conductors of infinite
length, of negligible circular cross-section, and placed 1 m apart in vacuum, would produce between these conductors a force equal to 2 x 10–7 Newton per meter of length
v. The Kelvin:
The Kelvin, unit of thermodynamic temperature, is the fraction of the thermodynamic temperature of the triple point of water. Is 273.16 K.
vi. The Mole: The mole is the amount of substance of a system which contains as many elementary entities as there are
atoms in 0.012 kilogram of carbon-12.
vii. The Candela: The candela is the luminous intensity, in a given direction, of a source that emits monochromatic
radiation of frequency 540 x 1012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.
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It can be defined as the unit of luminous intensity “the luminous intensity in the perpendicular direction
of surface square meter of a perfect black body at the temperature of freezing platinum under the pressure of 1.013255x105 N/m2 of that surface”.
Supplementary unit:1. RADIAN: This is the SI unit of (supplementary) plane angle. One radian is the plane angle between two
radii of a circle which cut off on the circumference of an arc equal to the length of the radian.2. STERADIAN: This is the SI unit of solid angle. One steradian is the solid angle which, with its vertex at
the centre of the sphere, cuts off an area of the surface of the sphere, equal to that of a square having sides of length equal to the radian of the sphere.
3. CURIE: This is the SI unit of radioactivity. One curie is the quantity of any radioactive substance which undergoes 3.7 x 1010 disintegrations per second.
2. British engineering system:In addition to SI system of units, another system of units is the British engineering system (sometimes called the conventional system), is still used in the United States despite acceptance of SI by the rest of the world. In this system, the units of length, force, and time are the foot (ft), pound, and second, respectively. In this system mass is derived quantity of unit “slug”. After fixing the units of fundamental quantities, the units of any other quantities are easily derived. For example, Force, F = m aF= 1kg. 1m / sec²1Newton = 1kg.m sec-²
Similarly, for other derived units are derived for derived quantities from their formulae.The constant value of acceleration due to gravity is 9.8 m / sec² in MKS system, 980 cm / sec² in CGS system and 32 ft / sec² in FPS system of units. F = m a One pound = 1 slug 1ft. sec- 2
1 slug = one pound / 1ft. sec- 2
1 slug = 4.45 N / 0.3048 m sec- 2
1 slug = 14.60 kg.
The conversion of mass in CGS and MKS system of units:
10 milligram = 1 centigram1 gram = 1x10-3 kilogram 10 centigram = 1decigram 10 decigram = 1 gram 10 gram = 1decagram10 decagram = 1 hectogram10 hectogram = 1 kilogram10 kilogram = 1 miriagram10 miriagram = 100 kilogram = 1 quintal 10 quintal = 1 metric tone1kg= 2.21 lb = 2.06x1026 a.m.u = 0.0685 slug1slug= 32.2lb = 14.6 kg.1amu= 1.66x10-27kg
Other units of length in MKS and CGS systems:10 millimeter = 1centimeter 10 centimeter = 1 decimeter 10 decimeter = 1 meter 10 meter = 1 decameter 10 decameter = 1hectometer 10 hectometer = 1 kilometer 1 hectometer = 100 meters10 kilometer = 1 miria meter1 m = 39.4 in = 3.23 ft
1 mile = 1.61km = 5280 ft1 km = 0.621 miles1 angstrom =10-10m1 light year = 9.46x1012 km= 9.46x1015 m1 parsec = 3.26 light year 1 parsec= 3.084x1013 km1 fathom= 6 ft 1 Fermi= 1 femto meter = 1015 m
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Units of length in FPS system:12 inches = 1 foot3 foot = 1 yard220 yard = 1 furlong
1760 yard = 1mile = 8 furlong =63, 360 inches
Relation between units of length in different systems:1 inch = 2.54 cm1 foot = 30.48 cm1 mile = 160934 cm
1 cm = 0.3937 inch1 meter = 39.37inch = 1.094 yard1 kilometer = 0.621 mile
Force:1 lb= 4.45 N 1 N= 105 dyne = 0.225 lb Energy and power:1joule= 107erg =2.78x10-7 kWh1 electron volt =1.6x10-19 joule=1.6x10-12 erg
1 horse power = 746 watts = 550Ft.Pound /sec
7: Dimension: The word dimension has a special meaning in physics. It usually denotes the physical nature of a quantity. Whether a distance is measured in the length unit feet or the length unit meters, it is still a distance. We say the dimension—the physical nature—of distance is length.For example, the symbol we use for speed is v, and in our notation the dimensions of speed are written, as [LT-1] another example, the dimensions of area, for which we use the symbol A, are The dimensions of area, volume, speed, and acceleration are listed in below, as well as other quantities:
Quantity Definition Formula Units Dimensions
MECHANICAL
Length or Distance fundamental D m (meter) [ L ]Time fundamental T s (second) [ T ]Mass fundamental M kg (kilogram) [ M ]Area distance2 A = d2 m2 [ L2 ]Volume distance3 V = d3 m3 [ L3 ]Density mass / volume d = m/V kg/m3 [ M L-3 ]Velocity distance / time v = d/t m/s [ L T-1 ]Acceleration Velocity / time a = v/t m/s2 [ L T-2 ]Momentum mass × velocity p = mv kg·m/s { M L T-1 ]Force or Weight Mass×
accelerationMass× (acceleration. of gravity)
F = maW = mg
N (Newton) = kg·m/s2
[ M L T-2 ]
Pressure or Stress force / area p = F/A Pa (Pascal)=N/m2 = kg/(m·s2)
[ M L-1 T-2 ]
Energy or WorkKinetic EnergyPotential Energy
Force × distancemass × velocity2/ 2mass× (Acc: gravity)× height
E = FdK.E=1/2mv2
PE = mgh
J (joule)=N·m=g·m2/s2
[ M L2 T-2 ]
Power energy / time P = E/t W (watt)=J/s = kg·m2/s3
[M L2 T-3 ]
Impulse force × time I = Ft N·s = kg·m/s [M L T-1 ]Action energy × time
momentum × distanceA = EtA = pd
J·s = kg·m2/s [M L2 T-1 ]
ANGUL
Angle FundamentalΘ
°(degrees) or rad (radians) 360° = 2π rad
Dimension less
Cycles fundamental N cyc (cycles) Dimension lessFrequency cycles / time f = n/t Hz (hertz) = cyc/s = [ T-1 ]
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AR
1/ sAngular Velocity angle / time ω = θ/t rad/s = 1/ s [ T-1 ]Angular acceleration
angular velocity/ time α = ω/t rad/s2 = 1/ s2 [ T-2 ]
Moment of Inertia mass × radius2 I = m r2 kg·m2 [ M L2 ]Angular Momentum Radius × momentum
mom. Of inert.× (angular velocity)
L = r pL = I ω
kg·m2/s [ M L2T-1 ]
Torque Radius × force mom. of inert.×(angular acceleration)
T = r FT = I α
N·m = kg·m2/s2 [ M L2 T-2 ]
THERMAL
Temperature fundamental T °C (Celsius) or K (Kelvin)
[ K ]
Heat heat energy Q J (joule) = kg·m2/s2 [ M L2 T-2 ]Entropy heat / temperature S = Q/T J/K [ M L2 T-2 K-1 ]
ELECTRO
MAGNETIC
Electric Charge(+/-) Current× time Q C (coulomb) [ C ]Current charge / time i = q/t A (amp) = C/s [ C T-1]Voltage or Potential energy / charge V = E/q V (volt) = J/C [ M L2 C-1 T-2 ]Resistance voltage / current R = V/i Ω (ohm) = V/A [ M L2 C-2 T-1 ]Capacitance charge / voltage C = q/V F (farad) = C/V [ C2 T2 M-1 L-2 ]Inductance voltage/(current/ time) L =
V/(i/t)H (Henry) = V·s/A [ M L2 T-2 ]
Electric Field voltage / distance force / charge
E = V/dE = F/q
V/m = N/C [ M L C-1 T-2 ]
Electric Flux electric field ×area φE = EA V·m = N·m2/C [ M L3 C-1 T-2 ]Magnetic Field force / (charge ×
velocity)B = F/qv T (tesla)= Wb/m2 =
N·s/(C·m)[ M C-1 T-1]
Magnetic Flux magnetic field × area φM = BA Wb (Weber)=V·s= J·s/C
[ M L2 C-1 T- 1]
8: Significant Figures:When physical quantities are measured, the measured values are known only to within the limits of the experimental uncertainty. The value of this uncertainty can depend on various factors, such as the quality of the apparatus, the skill of the experimenter, and the number of measurements performed. The concept of significant figures is often used in connection with rounding.When multiplying several quantities, the number of significant figures in the final answer is the same as the number of significant figures in the least accurate of the quantities being multiplied, where “least accurate” means “having the lowest number of significant figures.” The same rule applies to division.
When numbers are added or subtracted, the number of decimal places in the result should equal the smallest number of decimal places of any term in these.The rules for identifying significant digits when writing or interpreting numbers are as follows:
1. All non-zero digits are considered significant. Ex: 1, 20, and 300 all have one significant figure. Their significant figures are 1, 2, and 3 respectively. 123.45 have five significant figures: 1, 2, 3, 4 and 5.
2. Zeros appearing anywhere between two non-zero digits are significant. Example: 101.12 have five significant figures: 1, 0, 1, 1 and 2.
3. Leading zeros are not significant. For example, 0.00012 has two significant figures: 1 and 2.Trailing zeros in a number containing a decimal point are significant. For example, 12.2300 have six significant figures: 1, 2, 2, 3, 0 and 0. The number 0.000122300 still has only six significant figures (the zeros before the 1 are not significant). In addition, 120.00 have five significant figures. This convention
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clarifies the precision of such numbers; for example, if a result accurate to four decimal places is given as 12.23 then it might be understood that only two decimal places of accuracy are available. Stating the result as 12.2300 makes clear that it is accurate to four decimal places.
4. The significance of trailing zeros in a number not containing a decimal point can be ambiguous. For example, it may not always be clear if a number like 1300 is accurate to the nearest unit (and just happens coincidentally to be an exact multiple of a hundred) or if it is only shown to the nearest hundred due to rounding or uncertainty. Various conventions exist to address this issue:
5. A bar may be placed over the last significant digit; any trailing zeros following this are insignificant. For example, 1300has three significant figures (and hence indicates that the number is accurate to the nearest ten).
6. The last significant figure of a number may be underlined; for example, "20000" has two significant figures.
7. A decimal point may be placed after the number; for example "100." indicates specifically that three significant figures are meant.
A number with all zero digits (e.g. 0.000) has no significant digits, because the uncertainty is larger than the actual measurement.
Short questions and Answers
Question #1What is an atomic clock?An atomic clock is a clock that keeps time using natural characteristic frequencies of atoms, such as cesium, hydrogen or rubidium. Atomic clocks are extremely stable because the atom's characteristic frequencies are not affected by factors like temperature, pressure or humidity.
Question #2How long is a nanosecond, a picoseconds or a femto second? A nanosecond is one billionth of a second, and picoseconds are one trillionth of a second. Timekeeping technology has not yet reached the stage where we can measure femto seconds. However, just for the record, a femto second is a thousand times smaller than picoseconds!
Question #3What is an atomic Balance? Atomic balances, which are capable of measurement of nano particles mass, are described. The precision of measurements is defined by the geometry of measuring micro console and may be as high as 10-19 g. Atomic balance can also measure lateral stress and surface tension in thin films (also in mono layers). Experimental data on the atomic balance usage as highly sensitive gas and liquid analyzers, chemical and biological sensors are presented
Quantity UNIT Alternatives Definition/NotesA:Acceleration, angular s-2 rad.s-2 [Angular Velocity] /
[Time].
Abbé number 1 Dimensionless Inverse of refractive index.
Absorbed radiation dose m2.s-2 J.kg-1, Gy [Energy] / [Mass].
Absorbed dose rate m2.s-3 Gy.s-1 [Absorbed dose] / [Time].
Acceleration, linear m.s-2 [Velocity] / [Time]
Action kg.m2.s-1 J.s [Energy] [Time].
Activity of radioactive source s-1 Bq [Events] / [Time].
Angular acceleration s-2 rad.s-2 [Angular Velocity] / [Time].
Angular moment of inertia kg.m2 [Mass] [Distance2].
Angular moment of motion kg.m2.s-1 J.s [Moment of motion] [Distance]. Like [action].
Angular velocity s-1 rad.s-1 [Plane angle] / [Time].
Area m2 [Distance] [Distance].
B:Baud rate bit.s-1 Baud [Information] / [Time]
Also: information flux.
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Bulk modulus kg-1.m.s2 Pa-1 [Pressure] / ([Volume] / [Volume]).
Same as compressibility.C:Capacitance, electric kg-1.m-2.s4.A2 C.V-1, F [Charge] / [Potential]
Circulation m2.s-1 J.s.kg-1 [Angular moment of motion]/[Mass]
Characteristic impedance kg.m2.s-3.A-2 V.A-1, Ω, ohm √ ([Mag.Permeability] / [El.Permittivity]).
Charge, electric s .A C [Current] [Time]
Charge, quantum 1 Dimensionless [Charge] / [Elementary charge quantum]
Charge, molecular/ionic,
quantum1 Dimensionless [Charge of a molecule or
ion] /[Elementary charge quantum]
Charge density m-3.s.A C.m-3 [Charge] / [Volume]
Charge/mass ratio kg-1.s.A C.kg-1 [Charge] / [Mass]. Same as specific charge.
Charge, molar s.A.mol-1 C.mol-1 [Charge] / [Quantity]
Chemical potential, molar kg.m2.s-2.mol-1 J.mol-1 [ΔInternalEnergy] / [Quantity Of Substance].
Collision cross section m2 [Distance] [Distance]. Same as cross section.
Compressibility kg-1.m.s2 Pa-1 [Pressure] / ([Volume] / [Volume]).
Same as bulk modulus.Compression modulus kg-1.m.s2 Pa-1 [Pressure] / ([Volume] /
[Volume]).
Same as compressibility.Concentration, molar m-3.mol [Quantity] / [Volume].
Same as molar density.
Concentration, by mass 1 Dimensionless [Mass of substance] / [Total mass].
Same as mass concentrationConcentration, by volume 1 Dimensionless [Volume of substance] /
[Total volume].
Same as volume concentration.
Concentration, by weight 1 Dimensionless [Mass of substance] / [Total mass].
Same as mass concentrationConductance, electric kg-1.m-2.s3.A2 A.V-1, S [Current] / [Potential].
Inverse of resistance.
Conductivity, electric kg-1.m-3.s3.A2 S.m-1 1 / [Resistivity].
Conductivity, molar kg-1.s3.A2.mol-1 S.m2.mol-1 [El.conductivity] / [Concentration].
Conductivity, thermal kg.m.s-3.K-1 W.m-1.K-1 [Heat flux] / ([Distance] [ΔTemperature]).
Convergence m-1 dioptry in optics, but not only ...
Count rate s-1 [Events] / [Time].
Cross section m2 [Distance] [Distance].
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Cryoscopic constant kg.mol-1.K K/(mol/kg) [ΔTemperature] / [Molality].
Current, electric A A
Current density (electric) m-2.A [Current] / [Area]. Same as current intensity.
Current intensity (electric) m-2.A [Current] / [Area]. Same as current density.
Current noise, variance nJ2 s.A2 A2/Hz [Current]2 / Bandwidth]
Curvature radius m of a line in plane/space or surface in space
D:Density of electric charge m-3.s.A C.m-3 [Charge] / [Volume]
Density of electric current m-2.A [Current] / [Area]. Same as current intensity.
Density of energy kg.m-1.s-2 J.m-3 [Energy] / [Volume].
Density of mass kg.m-3 [Mass] / [Volume]. Same as specific density.
Density of substance m-3.mol [Quantity] / [Volume]. Same as concentration.
Dielectric constant 1 Dimensionless [Permittivity] / [Permittivity of vacuum].
Same as relative permittivity.
Dielectric strength kg.m.s-3.A-1 V.m-1 [Potential] / [Distance]. Same as electric strength.
Diffusion coefficient m2.s-1 [Distance2] / [Time].
Diffusivity, thermal m2.s-1 ([∂Temperatute] / [∂Time]) / [∇2Temperature].
Dipole moment, electric m.s.A C.m [Charge] [Distance]
Dipole moment, magnetic m2.A J.T-1 [Current] [Area]
Dispersive power 1 Dimensionless Ratio of differences of refractive indices.
Dispersivity quotient m-1 [Refractive index] / [ΔWavelength]
Distance m in all Euclidean n-dimensional spaces.
Dose of absorbed radiation m2.s-2 J.kg-1, Gy [Energy] / [Mass].
Dose rate m2.s-3 Gy.s-1 [Absorbed dose] / [Time].
Drift speed m.s-1 Steady-state speed of an object. .
Duration s s
Dynamic viscosity kg.m-1.s-1 Pa.s ([Force] [Area]) / [Velocity]
E:Ebullioscopic constant kg.mol-1.K K/(mol/kg) [ΔTemperature] /
[Molality].
Electric capacitance kg-1.m-2.s4.A2 C.V-1, F [Charge] / [Potential]
Electric charge s .A C [Current] [Time]
Electric conductance kg-1.m-2.s3.A2 A.V-1, S [Current] / [Potential]. Inverse of resistance.
Electric conductivity kg-1.m-3.s3.A2 S.m-1 1 / [Resistivity].
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Electric conductivity, molar kg-1.s3.A2.mol-1 S.m2.mol-1 [El.conductivity] / [Concentration].
Electric current A A
Electric dipole moment m.s.A C.m [Charge] [Distance]
Electric field strength kg.m.s-3.A-1 V.m-1 [Potential] / [Distance].
Also called electric intensityElectric field gradient kg.s-3.A-1 V.m-2 [ΔEl.field strength] /
[Distance].
Electric flux density m-2.s.A C.m-2 [Charge ] / [Area].
Also called electric induction
Electric inductance kg.m2.s-2.A-2 V.s.A-1, H [Potential] / [current / dt ]
Electric induction m-2.s.A C.m-2 [Charge] / [Area].
More properly electric flux density
Electric intensity kg.m.s-3.A-1 V.m-1 [Potential] / [Distance].
More properly electric field strength
Electric permittivity kg-1.m-3.s4.A2 F.m-1 [El.flux density] / [El.field strength].
Electric permittivity, relative 1 Dimensionless [Permittivity] / [Permittivity of vacuum].
Same as dielectric constant.Electric polarization m-2.s.A C.m-2 [Charge] / [Area]. Like
electric flux density
Electric potential kg.m2.s-3.A-1 W.A-1, J.C-1, V [Power] / [Current], [Energy] / [Charge]
Electric quadrupole moment m2.s.A C.m2 [El.dipole] [Distance]
Electric resistance kg.m2.s-3.A-2 V.A-1, Ω [Potential] / [Current]
Electric resistivity kg.m3.s-3.A-2 Ω.m ([Resistance] [Length]) / [Area].
Electric strength kg.m.s-3.A-1 V.m-1 [Potential] / [Distance].
Also called dielectric strength.
Electromagnetic vector potential
kg.m.s-2.A-1 V.s.m-1, T.m [El.field strength] [Time],
[Mag.flux density] [Distance]
Electromotive force (emf) kg.m2.s-3.A-1 V [Potential]
Electrostriction coefficient kg-2.m-2.s6.A2 m2.V-2 ([ΔVolume] / [Volume]) / [Electric field strength]2.
Energy kg.m2.s-2 N.m, J [Force] [Distance], [Power] [Time].
Energy, molar kg.m2.s-2.mol-1 J.mol-1 [Energy] / [Quantity].
Energy, specific m2.s-2 J.kg-1 [Energy] / [Mass].
Energy density kg.m-1.s-2 J.m-3 [Energy] / [Volume].
Energy flux kg.m2.s-3 J.s-1, W [Energy ] / [Time]. Same as power.
Enthalpy kg.m2.s-2 J Like energy and heat.
Enthalpy, molar kg.m2.s-2.mol-1 J.mol-1 [Enthalpy] / [Quantity]. Like molar heat.
Enthalpy, specific m2.s-2 J.kg-1 [Enthalpy] / [Mass]. Like
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specific heat.
Entropy kg.m2.s-2.K-1 J.K-1 [Heat] / [Temperature].
Entropy, molar kg.m2.s-2.K-1.mol-1 J.K-1.mol-1 [Entropy] / [Quantity].
Entropy, specific m2.s-2.K-1 J.K-1.kg-1 [Entropy] / [Mass].
Evolution rate on log-scale s-1 d{ln(Q)} / dt = (dQ / dt) / Q.
Also relative evolution rate.Expansion coefficient, thermal
K-1 ([Length] / [Length]) / [Temperature].
Exposure kg-1.s.A C.kg-1 [Charge] / [Mass]. Used for ionizing radiations.
Extinction coefficient m-1 In transmission of a radiation through space.
F:Force kg.m.s-2 N [Mass] [Acceleration].
Force, thermodynamic kg.m.s-2.mol-1 N/mol [Chemical potential] / [Distance].
Free energy kg.m2.s-2 J Also Helmholtz function. Like energy.
Free energy, molar kg.m2.s-2.mol-1 J.mol-1 [Free energy] / [Quantity].
Also molar Helmholtz function.
Free energy, specific m2.s-2 J.kg-1 [Free energy] / [Mass].
Also specific Helmholtz function.
Free enthalpy kg.m2.s-2 J Also Gibbs function. Like energy.
Free enthalpy, molar kg.m2.s-2.mol-1 J.mol-1 [Free enthalpy] / [Quantity].
Also molar Gibbs function.Free enthalpy, specific m2.s-2 J.kg-1 [Free enthalpy] / [Mass].
Also specific Gibbs function.
Frequency of waves or events s-1 Hz
Frequency drift rate s-2 Hz.s-1 [Frequency] / [Time].
Friction coefficient 1 Dimensionless [Tangential force] / [Normal force].
Fugacity kg.m-1.s-2 Pa Effective pressure in real gases.
G:g-factor of a particle 1 Dimensionless [Magnetic moment] /
([Spin].[Bohr magneton])
Gradient, of electric field kg.s-3.A-1 V.m-2 [ΔEl.field strength] / [Distance].
Gradient, of magnetic field kg.m-1.s-2.A-1 T.m-1 [ΔMag.flux density] / [Distance].
Gradient, thermal K.m-1 [ΔTemperature] / [Distance].
Same as temperature gradient.
Gravitational field intensity m.s-2 [Force] / [Mass], [Acceleration].Same as
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gravityGravitational field potential m2.s-2 [Energy] / [Mass].
Gravity m.s-2 [Force] / [Mass], [Acceleration].
Same as grav. field intensityGyromagnetic ratio kg-1.s.A Hz.T-1 [Mag.moment] / [Angular
moment of motion].
H:Half life s typically of a radioactive
substance
Hamiltonian kg.m2.s-2 J [Force] [Distance], [Power] [Time]. Like energy.
Hardness kg.m-1.s-2 N.m-2 [Force] / [Area]
Heat kg.m2.s-2 J Like energy.
Heat, molar kg.m2.s-2.mol-1 J.mol-1 [Heat] / [Quantity].
Heat, specific m2.s-2 J.kg-1 [Heat] / [Mass].
Heat capacity kg.m2.s-2.K-1 J.K-1 [Heat] / [ΔTemperature].
Heat capacity, molar kg.m2.s-2.K-1.mol-1 J.K-1.mol-1 [Heat capacity] / [Quantity].
Heat capacity, specific m2.s-2.K-1 J.K-1.kg-1 [Heat capacity] / [Mass].
Heat | Thermal conductivity kg.m.s-3.K-1 W.m-1.K-1 [Heat flux] / ([Distance] [ΔTemperature]).
Heat flux kg.m2.s-3 J.s, W [Heat] / [Time]. Like power.
Heat flux density kg.s-3 W.m-2 [Heat flux] / [Area]. Same as irradiance.
I:Illuminance cd.sr.m-2 lm.m-2, lx [Luminous flux] / [Area].
Impedance, characteristic kg.m2.s-3.A-2 V.A-1, Ω, ohm √ ([Mag.Permeability] / [El.Permittivity]).
Impact resistance kg.s-2 J.m-2 [Energy] / [Area]
Inductance kg.m2.s-2.A-2 V.s.A-1, Wb.A-1, H [Potential] / [dCurrent/dt], [Mag.flux] / [Current]
Induction, electric m-2.s.A C.m-2 [Charge] / [Area].Same as electric flux density
Information bit-1 bit One bit is the elementary information quantum.
Information flux bit.s-1 Baud [Information] / [Time]. Also called baud rate.
Intensity of electric current m-2.A [Current] / [Area]. Same as current density.
Internal energy kg.m2.s-2 J Like energy and heat.
Internal energy, molar kg.m2.s-2.mol-1 J.mol-1 [Internal energy] / [Quantity]. Like molar heat.
Internal energy, specific m2.s-2 J.kg-1 [Internal energy] / [Mass]. Like specific heat.
Ion mobility kg-1.m-1.s2.A m2.s-1.V-1 [Velocity] / [Electric field strength].
Ionic force (strength) m-3.mol Sum ([Concentration] [Ionic quantum charge]2).
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Ionic quantum charge 1 Dimensionless [Ion charge] / [Elementary charge quantum]
Ionic strength (force) m-3.mol Sum ([Concentration] [Ionic quantum charge]2).
Irradiance kg.s-3 W.m-2 [Heat flux] / [Area]. Same as heat flux density
J:Joule-Thomson coefficient kg-1.m.s2.K K.Pa-1 [Temperature] / [Pressure].
K:Katalytic activity mol.s-1 katal [Quantity] / [Time].
Same as molar production rate.
Kinematic viscosity m2.s-1 [Dynamic viscosity] / [Density]
K-space vector m-1 Same as reciprocal space position.
L:Lagrangian kg.m2.s-2 J [Force] [Distance],
[Power] [Time]. Like energy.
Length m m
Logarithmic ratio logb(A/A') 1 log in any base b Applicable to any ratio of like quantities.
Logarithmic ratio ln(A/A') 1 Np neper. Uses natural logarithm.
Logarithmic ratio Log(P/P')/10
1 dB Decibel. Uses base-10 logarithm. Aplies only to power P.
Logarithmic ratio Log(X/X')/20
1 dB Decibel. Aplies to voltages (X = V) and currents (X = I).
Logarithmic scale differential 1 Dimensionless dQ / Q , d{ln(Q)}, for any quantity Q
Also relative differential.Luminance cd.m-2 [Luminosity] / [Area]
Luminosity cd cd Same as luminous intensity.
Luminous flux cd.sr lm [Luminosity] [Solid angle]
Luminous intensity cd cd Same as luminosity.
M:Magnetic dipole moment m2.A J.T-1 [Current] [Area]. Like
magnetic moment.
Magnetic field gradient kg.m-1.s-2.A-1 T.m-1 [ΔMag.flux density] / [Distance].
Magnetic field strength m-1.A [Current] / [Distance].
Also called magnetic intensity
Magnetic flux kg.m2.s-2.A-1 V.s, W.s.A-1, Wb [Potential] [Time], [Power] / [current / dt]
Magnetic flux density kg.s-2.A-1 Wb.m-2, T [Mag.flux] / [Area].
Also called magnetic induction.
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Magnetic induction kg.s-2.A-1 Wb.m-2, T [Mag.flux] / [Area].
More properly magnetic flux density.
Magnetic intensity m-1.A [Current] / [Distance].
More properly magnetic field strength
Magnetic moment m2.A J.T-1 [Current] [Area]
Magnetic permeability kg.m.s-2.A-2 H.m-1 [Mag.flux density] / [Mag.field strength].
Magnetic permeability, relative
1 Dimensionless [Permeability] / [Permeability of vacuum].
Magnetic quadrupole moment
m3.A m.J.T-1 [Mag.dipole] [Distance]
Magnetic susceptibility 1 Dimensionless [Relative permeability]-1.
Magnetization m-1.A [Mag.moment] / [Volume].
Like magnetic field strength.
Magnetogyric ratio kg.s-1.A-1 T.Hz-1 [Angular moment of motion] / [Mag.moment].
Magnetomotive force (mmf) A [Current] [Number fo turms]
Magnitude of a star 1 Dimensionless M - m'= -100.4 (S/S'), whereS,S' are the luminous fluxes of two stars.
Mass kg kg
Mass density kg.m-3 [Mass] / [Volume]. Same as specific density.
Mass concentration 1 Dimensionless [Mass of substance] / [Total mass].
Also concentration by weight.
Mass flow kg.s-1 kg [Mass] / [Time].
Same as mass production rate.
Mass production rate kg.s-1 [Mass] / [Time]. Same as mass flow.
Mass, molar kg.mol-1 [Mass]/[Quantity]
Modulus of compression kg-1.m.s2 Pa-1 [Pressure] / ([ΔVolume] / [Volume]).
Same as compressibility.Modulus of rigidity kg.m.s-2 N, N.rad-1 [Force] / [ΔAngle]. Same as
shear modulus.
Mobility, ionic kg-1.m-1.s2.A m2.s-1.V-1 [Velocity] / [Electric field strength].
Molality kg-1.mol mol/kg [Quantity] / [Mass]. A way to specify concentration of a solution.
Molar charge s.A.mol-1 C.mol-1 [Charge] / [Quantity]
Molar concentration m-3.mol [Quantity] / [Volume]. Same as concentration
Molar conductivity, electric kg-1.m-3.s3.A2.mol-1 S.m-1.mol-1 [El.conductivity] / [Concentration].
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Molar density m-3.mol [Quantity] / [Volume]. Same as concentration.
Molar energy kg.m2.s-2.mol-1 J.mol-1 [Energy] / [Quantity].
Molar enthalpy kg.m2.s-2.mol-1 J.mol-1 [Enthalpy] / [Quantity]. Like molar heat.
Molar entropy kg.m2.s-2.K-1.mol-1 J.K-1.mol-1 [Entropy] / [Quantity].
Molar free energy kg.m2.s-2.mol-1 J.mol-1 [Free energy] / [Quantity] Also molar Helmholtz function.
Molar free enthalpy kg.m2.s-2.mol-1 J.mol-1 [Free enthalpy] / [Quantity]. Also molar Gibbs function.
Molar heat kg.m2.s-2.mol-1 J.mol-1 [Heat] / [Quantity].
Molar heat capacity kg.m2.s-2.K-1.mol-1 J.K-1.mol-1 [Heat capacity] / [Quantity].
Molar internal energy kg.m2.s-2.mol-1 J.mol-1 [Internal energy] / [Quantity]. Like molar heat.
Molar mass kg.mol-1 [Mass] / [Quantity]
Molar production rate mol.s-1 katal [Quantity] / [Time]. Like katalytic activity.
Molar refractivity m3.mol-1 [( r2- 1 ) / (r2 +2 )] / [Concentration],
where r is the refractive index.
Molar relaxivity m3.s-1.mol-1 [Relaxation rate] / [Concentration].
Molar solubility m-3.mol [Quantity] / [Volume]. Same as concentration
Molar volume m3.mol-1 [Volume] / [Quantity].
Molarity m-3.mol [Quantity] / [Volume].
Same as concentration or molar density
Molecular quantum charge 1 Dimensionless [Charge of a molecule] / [ Elementary charge quantum]
Moment of force kg.m2.s-2 N.m [Force] [Distance].
Moment of motion kg.m.s-1 [Mass] [Velocity], [Mass flow] [Distance].
Mutual inductance kg.m2.s-2.A-2 V.s.A-1, Wb.A-1, H [Potential] / [dCurrent/dt], [Mag.flux] / [Current]
N:Notch resistance kg.s-2 J.m-2 [Energy ] / [Area]
O:Osmotic pressure kg.m-1.s-2 Pa
P:Peltier coefficient kg.m2.s-3.A-1 W.A-1, V [Heat flux] / [Current].
Permeability, magnetic kg.m.s-2.A-2 H.m-1 [Mag.flux density] / [Mag.field strength].
Permittivity, electric kg-1.m-3.s4.A2 F.m-1 [El.flux density] / [El.field strength].
Permittivity, relative 1 Dimensionless [Permittivity] / [Permittivity of vacuum]. Dielectric
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constant.
Phase angle 1 rad φ in exp( i(ωt + φ ))
Phase drift rate s-1 rad.s-1 [Phase angle] /[Time].
Pi coefficient, molar kg.m-1.s-2.mol-1 J.m-3 [ΔInternalEnergy] / [ΔVolume].
Piezzoelectric coefficient kg.m.s-3.A-1 V.m-1 [Electric field strength] / ([ΔLength] / [Length]).
Plane angle 1 rad
Polarization, electric m-2.s.A C.m-2 [Charge]/ [Area]. Like electric flux density.
Position vector m in all Euclidean n-dimensional spaces.
Potential, electric kg.m2.s-3.A-1 W.A-1, J.C-1, V [Power] / [Current], [Energy] / [Charge]
Power kg.m2.s-3 J.s-1, W [Energy] / [Time]. Equivalent to energy flux.
Prandtl number 1 Dimensionless [Kinematic viscosity] / [Thermal diffusivity].
Poynting vector kg.s-3 W.m-2 [El.field strength] / [Mag.field strength].
Like irradiance.Pressure kg.m-1.s-2 N.m-2, Pa [Force] / [Area].
Probability of an event 1 Real number lying in the interval [0,1].
Probability density on ln-scale
1 Np-1 [Probability] / [Natural-logarithmic ratio]
Q:Quadrupole moment, electric m2.s.A C.m2 [El.dipole] [Distance]
Quadrupole moment, magnetic
m3.A m.J.T-1 [Mag.dipole] [Distance]
Quantity of substance mol mol
Quantum charge 1 Dimensionless [Charge] / [Elementary charge quantum]
Quantum charge,molecular or ionic
1 Dimensionless [Molecule/ion charge] / [Charge quantum]
Quotient of dispersivity m-1 [Refractive index] / [ΔWavelength]
R:Radiance kg.s-3.sr-1 W.m-2.sr-1 ([Power] / [Area]) / [Solid
angle].
Radiation dose m2.s-2 J.kg-1, Gy [Energy] / [Mass].
Radiation dose rate m2.s-3 Gy.s-1 [Absorbed dose] / [Time].
Radioactivity s-1 Bq [Events] / [Time].
Radius of curvature m of a line in plane/space or surface in space
Ratio of like quantities 1 Dimensionless
Reciprocal space position m-1 Same as k-space vector.
Redox potential kg.m2.s-3.A-1 V Same as reduction potential.
Reduction potential kg.m2.s-3.A-1 V Same as redox potential.
Refractive index 1 Dimensionless Light speeds ration (in a medium) / (in vacuum).
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Refractivity, molar m3.mol-1 [( r2 - 1) / ( r2 + 2 )] / [Concentration]
Refractivity, specific m3.kg-1 [( r2 - 1) / ( r2 + 2)] / [Specific density],
Relative differential 1 Dimensionless dQ / Q, d{ln(Q)}, for any quantity Q.
Also log-scale differential.Relative evolution rate s-1 d{ln(Q)} / dt = (dQ / dt) / Q.
Also evolution rate on log-scale.
Relative permeability, magnetic
1 Dimensionless [Permeability] / [Permeability of vacuum].
Relative permittivity, electric 1 Dimensionless [Permittivity] / [Permittivity of vacuum]. Dielectric constant.
Relative variation 1 Dimensionless ΔQ/Q, for any quantity Q.
Relaxation rate s-1 1/ [Relaxation time]. Used in all branches of Science.
Relaxation time s Used in all branches of Science.
Relaxivity, molar m3.s-1.mol-1 [Relaxation rate] / [Concentration].
Resistance, electric kg.m2.s-3.A-2 V.A-1, Ω [Potential] / [Current]
Resistance to impact kg.s-2 J.m-2 [Energy] / [Area]. Same dimension as notch resistance.
Resistivity, electric kg.m3.s-3.A-2 Ω.m ([Resistance] [Length]) / [Area].
Reynolds number 1 Dimensionless [Velocity] [length] / [ Kinematic viscosity]
S:Seeback coefficient kg.m2.s-3.A-1.K-1 V.K-1 [Potential] / [Temperature.
Same as thermoelectric power.
Self-diffusion coefficient m2.s-1 [Distance2] / [Time].
Shear modulus kg.m.s-2 N, N.rad-1 [Force] / [ΔAngle].
Same as modulus of rigidity.
Solid angle 1 sr
Solubility, molar m-3.mol [Quantity] / [Volume]. Same as concentration
Specific charge kg-1.s.A C.kg-1 [Charge] / [Mass]. Charge/mass ratio.
Specific density kg.m-3 [Mass] / [Volume]. Same as density of mass
Specific energy m2.s-2 J.kg-1 [Energy] / [Mass].
Specific enthalpy m2.s-2 J.kg-1 [Enthalpy] / [Mass]. Like specific heat.
Specific entropy m2.s-2.K-1 J.K-1.kg-1 [Entropy] / [Mass].
Specific free energy m2.s-2 J.kg-1 [Free energy] / [Mass].
Also specific Helmholtz
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function.Specific free enthalpy m2.s-2 J.kg-1 [Free enthalpy] / [Mass].
Also specific Gibbs function.
Specific heat m2.s-2 J.kg-1 [Heat] / [Mass].
Specific heat capacity m2.s-2.K-1 J.K-1.kg-1 [Heat capacity] / [Mass].
Specific internal energy m2.s-2 J.kg-1 [Internal energy] / [Mass]. Like specific heat.
Specific refractivity m3.kg-1 [( r2 - 1 ) / ( r2 + 2 )] / [Specific density]
Specific volume m3.kg-1 [Volume] / [Mass].
Speed m.s-1 [Distance] / [Time]. Same as velocity.
Spin 1 Dimensionless of a quantum particle
Star magnitude 1 Dimensionless m - m' = -100.4 ( S / S' ), where
S,S' are luminous fluxes of two stars.
Surface density of charge m-2.s.A C.m-2 [Charge] / [Area]
Surface element m2 [Distance] [Distance]. Same as area
Surface energy kg.s-2 J/m2 [Energy] / [Area]. Same as surface tension.
Surface tension kg.s-2 N/m [Force] / [Length]. Same as surface energy.
Susceptibility, magnetic 1 Dimensionless [Relative permeability]-1.
Stress kg.m-1.s-2 Pa, N.m-2 [Force] / [Area]. Same as pressure.
T:Temperature K K
Temperature gradient K.m-1 [Temperature] / [Distance].
Same as thermal gradient.Tension kg.m-1.s-2 Pa, N.m-2 [Force] / [Area]. Like
pressure.
Thermal conductivity kg.m.s-3.K-1 W.m-1.K-1 [Heat flux] / ([Distance] [Temperature]).
Same as heat conductivity.Thermal diffusivity m2.s-1 ([∂Temperatute] / [∂Time]) /
[∇2Temperature].Thermal expansion coefficient
K-1 ([ΔLength] / [Length]) / [Temperature].
Thermal gradient K.m-1 [ΔTemperature] / [Distance].
Same as temperature gradient.
Thermodynamic force kg.m.s-2.mol-1 N/mol [Chemical potential] / [Distance].
Thermoelectric power | Thermo power
kg.m2.s-3.A-1.K-1 V.K-1 [Potential] / [ΔTemperature].
Same as Seeback coefficient.
Thomson coefficient kg.m2.s-3.A-1.K-1 W.K-1.A-1 [Heat flux] /
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([ΔTemperature] [Current]).
Time s s
Torque kg.m2.s-2 N.m [Force] [Distance].
Same as moment of force.V:van der Waals constant: a kg.m5.s-2 Pa.m6 a in (p+ a / V2) ( V - b) =
RT.van der Waals constant: b m3 b in ( p+ a / V2) ( V- b ) =
RT.van der Waals virial constant: A
kg-1.m5.s-2.mol-2 A in p =( n / V) RT+ ( n / V )2 (RTB – A ).
van der Waals virial constant: B
kg-1.m3.mol-1 B in p = ( n / V )RT + ( n / V)2 (RTB - A).
Variance of current noise nJ2 s.A2 A2/Hz [Current]2 / [Bandwidth]
Variance of voltage noise nV2 kg2.m4.s-5.A-2 V2/Hz [Voltage]2 / [ Bandwidth]
Vector potential, electromagnetic
kg.m.s-2.A-1 V.s.m-1, T.m [El.field strength] [ Time], [Mag.flux density] [Distance]
Velocity m.s-1 [Distance] / [Time]. Same as speed.
Verdet constant kg-1.m-1.s2.A1 rad.m-1.T-1 ([Angle] / [Length]) / [Magnetic flux density]
Virial coefficient: second kg.m5.s-2.mol-2 Pa.(mol.m-3)-2 A in p= (n / V) RT + A (n / V)2 + B (n / V )3 +C(n / V)4.
Virial coefficient: third kg.m8.s-2.mol-3 Pa.(mol.m-3)-3 B in p =( n / V) RT + a (n / V)2 + B (n / V)3 + C( n / V )4.
Virial coefficient: fourth kg.m11.s-2.mol-4 Pa.(mol.m-3)-4 C in p =( n / V )RT + A( n/V)2+B(n / V)3 + C( n / V)4.
Viscosity, dynamic kg.m-1.s-1 Pa.s ([Force] / [Area] ) / [ΔVelocity]
Viscosity, kinematic m2.s-1 [Dynamic viscosity] / [Density]
Voltage noise, variance nV2 kg2.m4.s-5.A-2 V2/Hz [Voltage]2 / [Bandwidth]
Volume m3 [Area] [Distance]
Volume concentration 1 Dimensionless [Volume of substance] / [Total volume]
W:Wavelength m [Wave velocity] /
[Frequency].
Wave number m-1 [Number of waves] / [Distance].
Work function kg.m2.s-2 J, eV [Energy] needed to remove an electron.
Y:Young modulus kg.m-1.s-2 N.m-2, Pa [Stress]/[ΔLength] /
[Length]).
CONSTANT VALUES
Prof: Najeeb Mughal, Edited by Tarvesh Kumar Page 19PREFIXES AND SUFFIXES
Speed of sound=331m/sec=1200km/h=1090 ft/sec1 mile per hour (mph) =1.47 ft/sec=0.447 m/sMass of earth = 5.98x1024 kgMean radius of earth = 6.37x106 m = 3960 mil Mean earth–sun distance=1.49x108 km=2.39x 105 milMean earth–moon distance=3.8 x105km=2.39 x105 milSpeed of light=3.00x108 m/sec=1.86 x105 miles /secCharge of electron and proton =1.6x10-19 coulombsMass of proton = 1.67x 10 –27 kgMass of electron = 9.11x 10 –31 kgElectric current: 1 abampere = 10 amperesElectric charge: 1 abcoulomb = 10 coulombsCapacitance: 1 abfarad = 109 farads = 1 gigafaradInductance: 1 abhenry = 10-9 Henry = 1 annoyerResistance: 1 abhor = 10-9 ohm = 1 nanoConductance: 1 abhor = 109 SiemensMagnetic flux density: 1 abets =10-4 tesla =1 gaussPotential: 1 abbot = 10-8 volt = 10 Nan voltsPower: 1 abaft = 10-7 watt = 0.1 microwattErg: 1 erg = 10-7 JDyne: 1 dyn = 10-5 NPoise: 1 P = 1 dyn s/cm2 = 0.1 Pa sStokes: 1 St = 1 cm2/s = 10-4 m2/sGauss: 1 G = 10-4 TOersted: 1 Oe = (1000/(4 )) A/mMaxwell: 1 Mx = 10-8 WbStilb: 1 sb = 1 cd/cm2 = 104 cd/m2
Magnetic flux: 1 baneberry = 10-8 Weber = 1MaxwellAtomic mass constant mu =1.660 538 73(13) ×10-27 kgAvogadro constant L, NA = 6.022141 99(47)×1023 mol-1
Bohr magneton µB = 9.274 008 99(37) × 10-24 J T-1
Boltzmann constant k = 1.380 650 3(24) × 10-23 J K-1 Electron charge e = 1.602 176 462(63) × 10-19 CElectron mass me = 9.109 381 88(72) × 10-31 kgFaraday constant F = 9.648 534 15(39) × 104 C mol-1
Loschmidt's constant NL= 2.686 777 5(47)×1025 m-3
Planck constant h = 6.626 068 76(52) × 10-34 J sProton mass mp =1.672 621 58(13) × 10-27 kgSpeed of light c = 2.997 924 58 × 108 m s-1
Neutron mass mn = 1.674 927 16(13) × 10-27 kg Stefan-Boltzmann constant = 5.670 400(40) × 10-8 W m-2 K-4
Newton's gravitational constant G= 6.673(10) × 10-11 N m2 kg-2
Permeability of vacuum µ0 =4×10-7NA-2=1.256637061×10-6 NA-2
Molar gas constant R= 8.314 472(15) J K-1 mol-1 Permittivity of vacuum 0 =8.854187 817× 10-12 F m-1
Molar volume = (ideal gas, 101.325 kPa) Vm 2.241 399 6(39) × 10-2 m3
mol-1
Prof: Najeeb Mughal, Edited by Tarvesh Kumar Page 20
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